Since it came up in private conversation, let's discuss GMail.
It's a privacy nightmare.
Did you know you agreed to let Google read the full content of every email you send and receive, for "advertising" purposes?
Were you aware that they aggressively try to block emails that aren't from Google or other large providers (e.g., Microsoft), even when the email and the server sending it, and the domain hosting it, rigorously comply with every standard?
So what can you do?
Here's what you can do:
Buy a domain. It doesn't have to be a .com; there are cheap top-level domains you can buy domains in, for as little as $3-5 a year.
Once you buy a domain, you need DNS hosting. Cloudflare DNS hosting is free.
So, pay for a Virtual Private Server (VPS) from one of the myriad VPS providers. The smallest one will do. That's about $5 or so a month.
Set up sendmail or a sendmail equivalent on it (e.g., postfix). It's not that hard.
Create an MX record for your domain pointed at the public IP address of your VPS.
Read up on SPF, DKIM, and DMARC records, and create those DNS records as well.
Bingo, you have a mailserver that can send and receive email.
Now just configure a local IMAP mail client (e.g., the mail app on your phone, Thunderbird, etc.) to use that mail server to send and receive mail.
You now have unlimited email addresses at the domain you purchased, you have significantly more privacy with respect to your email (and it'll be transmitted to/from your mail server via an encrypted TLS tunnel), and you can stop relying on GMail for your email.
It'll cost you whatever the monthly charge is for your VPS, and whatever the annual renewal fee is for the domain you bought.